Electric heating unit



May 5, 1925.

E. PROBST ELECTRIC HEATING UNIT Filed March 22; 1923 InvenLor Emil Probst:

Hi s ALLOTHGH- Patented May 5, 1925.

UNITED STATES PATENT oreiesq EMIL PROBST, OF CHARLOTTENBURG, GERMANY, ASSIGNOR TO COMPANY, A CORPORATION OF NEW YDRK.

GENERAL ELECTRIC ELECTRIC HEATING- UNIT.

Application filed March 22, 1923.

' To all whom it may concern:

Be it known that I. EMIL Puons'r, a citizen of the German Republic, residing at t harlottenburg, Germany; have invented 6 certain new and useful Improvements in Electric lleating Units, of which the following is a specification.

My invention relates to electric heating units, and has for its object to make it pos- 10 sible to load the heating resistance specially high. and therewith to obtain at the same time a specially great radiating efi'ect.

According to my invention the heating resistance is arranged in a spirally bent 5 quartz tube. which is closed and filled with an indifferent gas. Such a heating unit is particularly adapted for use in radiant heaters, or for like purposes. i

In the 2Q embodiment of my invention.

Referring to the drawing, a is a spirally bent quartz tube. 7) a heating resistance conductor situated therein. The leading-in wires for the heating resistance 6 are fused 25 in at the twoends of the quartz tube a, so

that the quartz tube a is closed perfectly airtight. This sealing of the ends of the quartz tube a around the leading-in wires may be accomplished in any suitable manner, for

-and a. drawing 15 shown one illustrative.

Serial No. 626,970,

example, by means of the blended seal process disclosed in United States Patent No. 1.173.688 to Elihu Thomson. The clesed tube a is filled with a gas which is indifi ercut as regardsithe resistance wire I). which gas causes the quartz tube a. As a filling gas, hydrogen or nitrogen are suitable.

The quartz tube a itself may assume a comparatively high temperature without danger of its being destroyed or coming permeable to gas.

What I claim as new and desire to secure by Letters Patent of the United States, is,--

1. An electric heating unit comprising a spirally bent quartz tube, said tube being closed and filled with an indifferent gas, resistance conductor extending through said tube.

2. An electric heating unit comprising a spirally bent quartz tube, a resistance condurtor in said tube extending throughout its length, and leadingdn wires for said resistance conductor, said tube having its ends sealed around said leading-in wires and being filled with an indifierent gas.

in witness whereof, I have hereunto set my hand this 27th day of February, 1923.

EMIL PROBST.

a good transmission of heat to :r'

of its 1112- 

